Preheat oven to 325 degrees.
Grease and flour two loaf pans.
Sift together the flour, baking powder, baking soda, salt, and cinnamon in a mixing bowl and set aside.
Beat together the eggs, oil, sugar, and vanilla in a large mixing bowl.
Add the wet ingredients to the dry ingredients and mix well.
Add the grated zucchini and mix well.
Divide evenly between the two loaf pans and bake for 40-60 minutes or until inserted toothpick comes out clean.
Cool for 20 minutes in the pans before transferring to a wire rack.